Hollow ingot and method of making same.



F. D. CARNEY.

HoLLow INGor AND METHOD oF MAKINGYSAME.

1.9%?7543 APPLICATION yFILED MAR. 23|` |918. 3, 3 SHEETS-SHEET l- N @W wno Q W65 l? @3 2 QH 5 Q f $7 @I 1k w f@ m N i is Q @l fr i r 'T W@ x l QN QN Q5 9i W w Q l* w s (J1/mudo@ @im @www vo i i 5% @3 M l (mouw,

F. D; CARNEY. n -HOLLDW INGOT AND METHOD 0F MAKING SAME.

Patented Se pt. 3,1918 3 SHEETS-SHEET 2.

APPLICATION FILED MAR. 23. I98.

Gufotue F`. D. CARNEY.

HOLLOW INGOT AND METHOD 0F MAKING SAME. APPLICATION FILED MAfLvzs. |918.

LQ7'543@ v PatentedSept.3,1918.

' tion.

naaien' n. canning, or nncmnnnnn, rnnnsrnvnnra To all 'whom t mayconcern.'

Be it known that FRANK D. a citizen of the United States, and a residentof Bethlehem, in the countyof Northampton and State of Pennsylvania, U.S. A.

have invented certain new-.and useful Img provements in Hollow Ingotsand Methods of Making Same; and I do hereby declare the following to bea full, clear, and exactdescription of the invention, such as willenable others skilled n the art to which it appertains to make and usethe same, being had to the accompanying drawings, and to letters orfigures of reference marked thereon,

Heretofore, in the production of the ingots cast in the customaryvertical method, it has been dicult to avoid pipe, segregation, surfacecracks and other defects; slag inclusions resultingA from reactions inthe mold revolving at a high speed on its' hori- A tio'n in the coolingmolten metal during solidification and inclusions from accidentaladditions of foreign matter. llt is also an impossibility to obtain auniform uniaxis crystalline condition in the ingots, due to the greatvariarate from the outside surface to the center.

To avoid the above trouble when casting ingots which areto be used forobjects with hollow centers; I have cast cylindrical and conical ingotswith a uniform cylindrical bore, by pouring the molten steel into thezontal axis, producing, thereby, a centrifugal force inl excessl of theforce of gravity.

j l found, for example, in the case of steel when poured or castdirectly on the iron or steel surface of an ordinary ingot moldrevolving on its horizontal aXis at a speed sufiicient to producecentrifugal force, that it was impossible to make an ingot free fromsurface defects, strains and cracks. `While the method of horizontalcentrifugalcasting is known in general, I believe that I am `the iirsttocast cylindrical and conical ingots of variable dimensions and weight.;in a practical way which are free romtje above enumerated defects. j

My ig. ention overcomes sald defects, and

`is a mfethod of casting hollow, cylindrical and conical ingots freefrom pipe, internal strains, surface cracks and' the customary internaldefects due to segregation and slag inclusions, in a practical way, bycasting rapidly under the action of centrifugal speemmion of Lettersraam. i

CARNEY, A

reference which form a part of this specifica-l nonnow meorai'tn nmrngonor nanntesans.

force in a suitable machine, one or a plurality of ingots from a singleladle of molten steel; controlling the relative rate of cooling of theinterior and exterior surfaces of the ingot; controlling the crystallinestructure of the ingot, vand rapidly removing the ingot with the moldfrom the revolving container thereo In' order to clearly define the modeof procedure, reference will be made to the accompanying drawings, inwhich like parts are similarly designated, and in which- Figure l is avertical longitudinal section of a machine such as I usevto produce theingots referred to.

Fig. -2 is a diagrammatic plan view, and

AFig. 3 an elevation of a plant for centrifugally casting the hollowingots.

Fig. t is a cross section, and

Fig. 5 is a longitudinal section, partly 4in elevation, of amoditication of the apparatus.

Fig. 6 is an elevation nal section, and

Fig. 7 an end view of a modiiied form of ingot mold, and

Fig. 8 is an elevation, partlygin section, of another form of such mold.

Figs. 9 and 10 are diagrammatic views of the manner of simultaneouslycasting a plurality of Vhollow ingots.

ln the apparatus 1 is the carrier` or drum of cast metal providedbetween its ends with a pair 'of tires or the equivalent, 2. Containedwithin the drum is the ingot mold 3 of sheet metal. This sheet metalmold 3 is held within the carrier or drum l by clamps, andv in thestructure shown the clamps 4 at the right hand end, Fig. 1, directlyengage one end of the sheet metal mold 3,'while at the other end thereofis an annular, trough shaped spill way 5, of brick, Figs. 1 and 9, or ofsheet metal 5, Fig. 10, fitting into the end of the drum 1 and engagedby the clamps 6. f

These clamps are-of well known construction, of angle shape 'and areadjustable longitudinally of the drum in slots therein.

The sheet metal molds 3 are not to make continuous surface contact withthe drum 1, and for this purpose they may have any desired projections,either longitudinal corrugations 3a, as in Figs. 4 and 5, orquincunXially arranged rounded bulges or projections 3", Figs. 6 and 7,or more pointed Droiections. as 3, Fig. 8.

partly in longitudi- Patented Sept.. 3, iljl. Y Applicatiton tiled March23, 1918. Serial No. 224,184.'

n for the insertion of a pulverulent or sandlike insulation of fireproofmaterial between the two concentric membersz "when 1t is desirable toemploy such material. i The dimensions of this interspace, as well asthe nature of the material included insaid space, whether air, or sand,dolomlte, 89o., controls the rate of solidificatlon, as with some steelsit is desirable that solidicationtakes place' quicker than with others.

Several such carrlers or drums 1 with their contained sheet metal molds3 are stored.

on an inclined track 7, and are temporarily l held by a chock 8.

At the end of the track 7 is located the,

centrifugal casting machine C, shown in detail in Fig. 1, and after thecasting of the ingot has been completed in this machine the carrier ordrum with the ingot therein is delivered to a second inclined track 8'having a depression 9 or equivalent means for arresting the travel ofthe carrier or l drum at a required point, where a suitable plungerdev-ice ,10 removes the ingot fromthe drum.

The carrier 1 with its contained ingot mold rolls down into thecentrifugal casting machine, Fig. 1, with its rails or flanges 2 restingbetween the flanges of four rollers 11. There is sufficient play betweenthe flanges of these rollers 11 and the sides of the flanges 2 on thedrum 1 to permit longitudinal reciprocation of the carrier during therapid rotation of the drum.

The carriers are also provided with auxiliary rails-13,- one near eachend of the carrier. Each of these rails 13 is engaged by a pair ofholdingldown rollers 14 for holding the drum on t e rollers llandpreventing the drum from jumping out of the machine durin the rapidrotation.

Eac air of holding down rollers is mounted 1n a yoke 15 pivoted at 16and connected at 4'17 to an eccentric rod 18 operatedP by an eccentric1-9 on a shaft 20. This shaft,

carries both eccentrics 19, set 180. apart for actuating the two yokes15, one for each end of the drum, as illustrated.

On the shaft 20 is a worm wheel 21 driven by a worm 22 on the shaft 23of a reversible electric motor 24.

'.On the drum 1, between the two main fianges 2- thereof, is a machinedsurface 25,

which is capable of being engaged 'by one or theother of twocurved arms26. .These curved arms 26 are capable of alternate engagement with thesurface 25 and are operimams ated by a` reversible electric motor`27.The arms 26 serve a double purpose, to brake the drum, and to lift thedrum Jand lts contained ingot out `of the machine onto the second track8 after the metal has been cast. v One end of the drum is rovided with aseries of recesses 28 into w ich engage the pins 29 of the hollow clutchmember 30, moved into and out of engagement with the drum by a shiftingyoke or ring 31, of any suit-able construction. The shaft 32 of theclutch 30 is hollow and carries a spur gear 33 driven by a drivingpinion 34. At the end of the shaft is a rotary blower 35 driven by abelt pulley 36.

After the'drum is in position in the machine, a spout or runner 37 isinserted through one end. The runner is provided with the customary trap38 into which the ladle discharges the metal. As soon -as the drum hasbeen brought upto speed the metal is poured.

The detailed procedure will be as follows The ingot is made by, firstpreparing an ingot mold 3 of thin sheet metalywhich may or may not be ofthe composition o'f the ingot to be formed. Usually it is not of thecomposition of an ingot, but of a cheaper metal. By using such a moldsupported in a mold carrier or drum it is possible to withdraw theingot, with its weld connected mold immediately after solidification,from the mold carrier. Thisis important, in that not only is theycarrier released for re-use at 100 once, but also the ingot can betransferred as 4 hot as possible toa furnace, soaking pit, or theequivalent, for controlling the rate of cooling. The ingot molds that Ihave used are about one-sixteenth of an inch in thickness for hollowingots of 18 diameter and 3 thickness of wall. The thickness of the wallof the ingot 'mold will vary directly with the size of the ingot, but ispreferably very thin, so that in subsequent manipula- 110 tion of themetal the entire ingot mold will be oxidized away.

The ingots with which I have yhad experience are of cylindrical andslightly conical shape, and are rotated at the high speed of about 3500peripheral feet per minute,

. more or less; the object being that the speed should be high enough toattain a heavy centrifugal force on the metal, sufficient to cause theelimination' ofMsegregation and 120 the slag, gasinclusions, andaccidental foreign matter, and to carry them to the surface of thehollow of the ingot.

The ends a of the ingot molds are constructed of the same material asthe body of 125 the molds, and are annular for forming the annular. endwalls of the ingots; the thickness of the ingot being controlled andmeas1 ured by the difference between the external and internal ldiameterof the annulus.v

and carrier to edectually prevent vide between the mold and space topermit thel insertion between the p carrier may be These molds may becylindrical, but, whatever their general' shape, I prefer to have` themcorrugated as'at 3a cal, as in Figs. 4 and 5. The corrugations may be ofany desired shape, and may run longitudinally or otherwise of the mold.The mold may also be so' constructed as to provide projections on itsouter surface, with the object of having the mold spaced at irregulardistances from its carrier, (such carrier being a metal speed drum, withits interior cylindrical or conical, in which the mold is supported androtated).

'The mold is centrally spaced from the inner surface of this drum, andthe intervening space may or may not be lled with an insulatingmaterial. rial is preferably ine and of a sand-like character; theobject being that the material should have a flow similar to that ofsand, in order to facilitate the withdrawal of the ingot and itsadhering mold from the carrier, to allow freedom of shrinkage both lon`gitudinally .and transversely,- and at the same time maintain andaccommodate insulation between the mold and carrier. At

the fsame time this insulating material will produce sucient frictionbetween the mold any slip between the two during .casting operations;l

While l have described the mold as being spaced from the carrier, thereis no objection to having corrugations, indentations or other protrudingsurfaces on the mold contacting with the carrier -at intervals, as shownat 3b and 3, Figs. (38. Y

'ln lieu of thecstructure just described, the

provided with internal projections or corrugations, or ll may, in somecases, use both corrugationsand projections; or the 4:mold may beprovided with longitudinal corrugations 3, and the carrier may beprovided with internal circumferential corrugations l", Figs. i and 5,so that the corrugations of the one will cross the corrugations of theother; the object being to procarrier suiiicient mold and carrier ofsome insulation material, to prevent to'o rapid chilling of the mold andingot. p

One of the great. .objects attained by such a structure with a thinsheet metal mold (this mold being spaced and insulated with aninsulating material) is that the liquid metal never comes into contactwith the insulating material; if it did, a slag might be v formed, orimpurities due to or contamed inthe insulating material might becomeincprpprated in the metal, so that the resulting metal obtained in theingot would not be .absolutely ofthe same purity as the metal introducedtherein. For high grade steel, this is a very important consideration.

ln order to facilitate the withdrawal of and slightly-coni-- Thisinsulating matethe ingot and mold from the carrier, especially when veryheavy ingots are cast, it is of advantage to make the ingot mold or thecarrier, or both, conical, Figs. 4.- Vand 5; that is to say, have aneasy drawing taper. The fine sand, having a iiow like sand, greatlyfacilitates the withdrawal of the ingot when either cylindrical orconical shapes are used.

The ingot mold is held in position in the carrier by, means ofadjustable clamps 6; the clamps being adjusted lengthwise of thecarrier, so that it is possible with a single carrier to cast ingots anylength, less than the length of the carrier.

he carrier is provided at one end, preferably at thev pouring end, witha second annular head 5, spaced so as to provide a metal trough orspill-way for excess metal; the object being that sufficient metal ispoured until the operator sees it iiow into the spill-way, by which hedetermines that `the mold is filled. This metal in the spillway iscropped or removed from the ingot before rolling or forging; or, in lieuof the spill-way formingl a part of the mold itself, I insert right nextto the end of the mold a refractory spill-Way 5, Fig. 9, so that whenthe ingot'is removed from the mold the spill-way metal will separatefrom it.

When casting several ingots in a single mold` there is provided atdistances apart equal to the length of the ingots, annular 'l walls offrangible, refractory material, as of lire brick, Fig. 9; or I insert inthe carrier short mold sections 113 spaced apart by lire brick Fig. 10.The fir placed within the mold, as .may be placed in the carrier molds113.

in operation, the molten metal must be poured into the rapidly rotatingmold at a much faster rate than when casting solid ingots; the ratebeing so great as to prevent solidification starting to any appreciableenteint efore the pouring of the ingot is comu ete p The practice thatlf have followed, and which l find especially successful isto pourmolten steel into the ingot mold at the rapid rate of four to fivethousand pounds per minute. For the same grade of steel in a solid ingotthe rate would be from one to two thousand pounds per minute; it beingunderstood that the rates of pouring for different grades of steel varyaccording to their composition, the temperature and the size and shapeofthe ingot mold. After pouring the metal into the mold andsolidiication .is completed, l immediately remove the carrier and itscontained ingot and mold from the centrifugal machine, strip the carrierat once from the mold and ingot, and place the' ingot and mold in aninsulating materialv soaking pit, or heating furnace, in

in Fig. 9, or it separating short e brick may be izo' Y llt@ titi

With 18 diameter ingots made by'me,`

the peripheral speed is so great that the 'pressure on the metal at theexternal surface of the ingot is in the neighborhood of 30 pounds persquare inch, and the pressure at the internal surface of such an ingotis in the neighborhood of 20 pounds per square inch, the thickness ofthe ingot walls being about three and `one-half inches. These pressurescan be accurately determined from the known speed and diameter of themold and container. As the diameter of the ingot increases, theperipheral pressure will increase and the speed of rotation may then beappreciably decreased. These pressures are suiiiciently great to force.toward the central inner surface any impurities, slags or gases, thatmay be in the metal.

Inaddition to the centrifugal' force due to rapid rotation of the ingot,I impart a longitudinal reciprocation, and this longitudinalreciprocation or agitation' assists in rapidly flowing the metal overthe entire surface of the mold and prevents the formationof coarsecolumnar crystals, normal to the surface, as ordinarily found invertically cast solid ingots.

In order to facilitate rapid solidification,

I inject, by means of blower 35, through the center of the hollow ingotimmediately after pouring, a current of air, to aid the solidication ofthe metal throughout its thickness as rapidly as possible, and also tocontrol the rate of cooling of the ingot, in proportion to thethickness; the rate of cooling being controlled by the volume andpressure of the air supply.

rIhe'rate of solidifioation of the ingot is also controlled byincreasing or decreasingy the space between the mold and the carrier,thereby varying the thickness of the insulating material vbetween themold and the carrier, and, where no solid insulating material iscontained between the mold and its carrier, the air trapped between themold and carrier acts in the-same manner.

The solidification is controlled so as to arrest segregation under thecasting conditions and according to the nature ofthe metal being cast.

I claim- 1. The method of casting hollow steel inof the metalthroughout' the mold.

2. 'Ihe method of casting hollow ingots, which comprises pouring moltenmetal into a mold maintained in rotation and longitul dinalreciprocation.

3. The method of casting hollow ingots, which comprises pouringmoltenmetal into an insulated metal container maintained in rotationsufficient to impart centrifugal action to the metal, and cause saidcontainer to become part of the ingot, and immediately removing theingot with its adherin oontainer. from the rotating device, an thenretarding its rate of cooling.

4. The method of casting hollow ingots, which comprises pouring moltenmetal into a sheet metal container having annular heads that determinethe thickness of the ingot while supported on insulating material andmaintained in rotation sucient to impart centrifugal action to themetal, whereby said container becomes welded to the ingot.

5. The method of casting hollow ingots, which comprises casting moltenmetal into a rotating sheet metal container at a temperature welding themetal. and container,

said container being of a thickness suiiicientl Ato oxidize 0H duringsubsequent manipulation of the metal, and maintaining its speed ofrotation sucient to overcome segregation.

6. The method of casting hollow ingots, which comprises casting moltensteel into a horizontal rotating thin metal mold hav# ing annular heads,and continuing the pour ing of the metalfuntil the metal in the moldspills through the central orifice at one end. l

`7. The method of casting hollow ingots, which comprises pouring moltensteel into a horizontal rotating thin metal mold having annular heads,and continuing the pourin of the metal until said metal spills throughthe central orifice at one end, and retaining the spilled metal in acompartment ad]acent the end of the mold.

8. The method of casting hollow ingots, which comprises pouring moltensteel into a horizontal rotatin thin sheet metal mold having annular heas; and continuing the pouring of the metal until said metal spillsthrough the central orifice in one of said heads, and retaining thespilled metal in a separate separable -compartment adjacent the end ofthe ingot.

9. The method of casting hollow ingots, which comprisesy pouringthe'molten metal into a horizontal rotating thin metal mold whilesupporting said mold within a drum,

maratea' and withdrawing the integral ingot and mold as soon assolidied.

10. The method .of casting hollow ingots, which comprises pouring themolten metal into a horizontal, rotating thin metal mold whilesupporting the mold within a drumi and immediately distributin the metalin the mold, said mold being su 'ciently thin to be'oxidized 0H duringsubsequentvmanipulation of the hot metal.

11. The-method of casting hollow ingots, which comprises pouringthe'molten metal into a rapidly rotating thin sheet metalmold supportedwithin a drum havin heat insulation between it and the said drum, andcontrolling the rate of solidification of the metal under centrifugalaction by the thickness of the said insulating material.

12. The method of casting hollow ingots, which comprises pouring .themolten metal into a horizontal, rapidly rotating, thin sheet metal moldin non-continuous surface contact with a s eed drum, said mold being ofsucient thic ess to be oxidized olf in subsequent manipulation of themetal.

13. The method of casting hollow ingots, which comprises pouring themolten metal into a horizontal, rapidly rotating, thin metal mold innon-continuous surface contact with a speed drum; the interior spacebetween said mold and drum containing a heat insulating material.

14. The method of casting hollow ingots, which comprises rapidly pouringthe molten metal into rotating thin sheet metal molds in non-continuoussurface contact with a speed drum, the interior space between said drumand molds containing a dry, pulverulent, highly refractory, insulatingmaterial.

15. The method of casting hollow ingots, which comprises rapidly pouringthe molten steel into thin corrugated sheet metal molds supported withina heavy metal drum heat insulated therefrom, and maintained in rapidrotation, removing the hot ingot immediately after solidication with itsadhering mold, and controlling the rate of cooling of the ingot.

16. The method of casting hollow ingots, which comprises pouring moltensteel into corrugated thin sheet metal ingot moldsA supported within aheavy metal drum heat insulated therefrom and maintained in rapidrotation, removing the hot ingot and its adhering mold immediately aftersolidification, andL controlling the cooling of the ingot by covering itup with insulating material.

17. The method of casting hollow steel\ ingots, which comprises rapidlypouring.;

molten steel into a sheet metal mold sufficiently thin to oxidize oillin the subsequent treatment of the steel ingot, said mold being rotatedat a speed suiiicient to instantly distribute the steel throughout themold and ,rapid rotation,

Iby external insulation and controlling the character of the steel bycontrolling the rate of soliditication by a current of air through theVinterior of the mold and ingot.

18. The method of casting hollow steel ingots, which comprises rapidlypouring molten steel into a sheet metal mold while in controlling thecharacter of the steel by controlling the rate of solidication of theingot both from the exterior and from the interior.

19. The method of casting hollow steel ingots, which comprises pouringmolten steel into a sheet metal mold while in rapidrotation at aspeedsuicient to cause an instantaneous distribution of the metal throughoutthe mold, and controlling the characterof the metal by externalinsulation of the mold and the pesage of a gaseous medium through theingot and mold.

2 0. 'lhe method of casting hollow ingots, which comprises pouringmolten metal into a rapidly rotating sheet metal mold and controllingthe rate of solidification of the ingot internal current of gaseousmedium, the temperature of the metal being sufficient to weld to saidmold.

21. rlhe method of casting hollow ingots, which comprises pouringmolten-metal into a rapidly rotating horizontal ingot mold and impartinga longitudinal reciprocation to said mold while directing a coolingmedium into the interior of the ingot.

22. A sheet metal -ingot mold whose exterior surface has elevations anddepressions and is in welded-connection with the ingot.

23. rlhe method ingots, which comprises pouring steel into a rotatingingot mold in excess of the quantity required to lill the mold, therebyimparting centrifugal pressure to the metal during' solidication andwashing from the of casting hollow steel.

interior of the hollow ingot any impurities V forced to the interiorsurface by centrifugal action, by the excess pouring operation. v

24.4. rlhe method of making hollow steel ingots, which comprises pouringmolten Steel into direct contact'with a rapidly rotating sheet metalmold having transversely arranged annular partitions, and separating theingots at the partitions.

25. The methd of making hollow ingots, which comprises pouring moltenmetal into a rapidly rotating sheet metal mold having transverselyarranged friable annular partitions, and separating the ingots at thepartitions. y

26. The method of making hollow 4steel ingots which comprises pouringmolten steel into direct contact with the interior of a sheet metal moldrotating ata speed suitlcient to impart centrifugal force to the steelwhen poured, separating the metal into ingots by annular partitions, thecharacter of metal' at the end of the the steel being controlled bycontrolling the time of solidification of the metal by a dry comminutedinsulating material.

27. The method of making hollow ingots, Which comprises supporting acorrugated sheet metal mold having annular" heads Within an interiorlycorrugated speed drum, corrugations of the mold and drum crossing oneanother, the interspace between the mold and drum containing a looseinsulating material capable of yielding to expansion of the mold,rotating said mold and drum at a Lemme speed .suflicient to impartcentrifugaly force to the contents of the mold, and simultaneouslylongitudinally reciprocating the drum, pouring molten metal into directv'contact with the interior of the drum until some of the metal spillsfrom the mold, and collecting the spilled metal in a Se aratecompartment in the drum adjacent t e mold.

In testimony that I claim the foregoing as my invention I have-signed myname hereto.

FRANK D. ,CARNE

